Crystal Structure of the (K0.87Bi0.13)BiO3Superconductor

✍ Scribed by N.R Khasanova; F Izumi; T Kamiyama; K Yoshida; A Yamamoto; S Tajima

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 118 KB
• Volume: 144
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1998.8170

✦ Synopsis

The structure of a superconducting oxide (K 0.87 Bi 0.13 )BiO 3 (T c +10.2 K) prepared under high pressure was analyzed by time-of-flight neutron powder diffraction. Rietveld refinement showed this compound to be a cubic perovskite ABO 3 with space group Pm3 m (No. 221) and lattice parameter a ‫؍‬ 4.23377(3) A s . Refinement of occupation factors revealed the absence of oxygen vacancies and the substitution of Bi 3؉ ions for 13% of K ؉ ions at the A site, presenting evidence for electron doping in this superconductor. Extraordinarily large atomic displacement parameters for the A and O sites are believed to reflect pronounced positional disorder mainly arising from the large difference in size between the K ؉ and Bi 3؉ ions.